The present invention relates to a hydraulically actuated starting clutch, and more specifically to a starting clutch assembly for a continuously variable transmission in an automotive vehicle. Continuously variable transmissions have been known for several years as a driving assembly between a vehicle engine and the road engaging wheels to provide a smooth acceleration without the usual shifting of gears found in most automatic transmissions. A continuously variable transmission can include variable sheave pulleys, an endless belt extending between and engaging the pulleys, and control means to alter the effective pulley diameters and thus change the speed ratio.
It automotive applications, it is necessary to incorporate a suitable clutch assembly in the drivetrain as a starting device and planetary gearing to effect desirable gear reduction and to provide for forward-neutral-reverse gear mechanisms. It is desirable to have the pulleys constantly rotating when the vehicle engine is running, even at an idle rpm, so that initiation of movement of the vehicle is accomplished by a throttle responsive friction starting device, such as a clutch, located at the output of the transmission, and a forward-neutral-reverse mechanism is preferably located in conjunction with or subsequent to the starting device.
Problems will arise in the resultant centrifugal force of a rotating clutch which traditionally provides liquid pressure that may influence actuation of the clutch. Further problems include engine stalling during rapid vehicle braking and lack of smoothness of clutch engagement during acceleration of the vehicle. The present invention overcomes these various problems in the form of a novel starting clutch assembly.